THE BIRD TICK. 99 
TaBLE XXIX.—Engorgement of larvx of Hemaphysalis chordeilis. 
Larve dropped engorged—days | 
Date following application. | Total | 
larve Host. x 4 | nme | State of engorgement. 
applied : dropped. | 
Bil Gee ouly- 8 OM TF | 12 
1909. 
Beep. «| sabbit....2--- Si S| RP 2 OP ah O | 0} 21 | Fully. 
Peiicedes | HOne = 255 2S TOs Ob Onl Or Orb Ol 6-1) (0: 0 | 
Sept. 17 | Guinea pig 7 al ees Re ee Descent Sf teretiow | 2 | Fully. 
mt, 18 f Hen. ....2.;.- Cr Of 0.) 0) 87°04 081.6) 0 : 
Sept. 22 | Rabbit...:..-- MG ek dl mh Ue Sa i US ES St 3 | Two-thirds to fully. 
Sept. 24 |..... G0. 25 =.4-- my 81 OF Oo) 2) sf 2). ), 2 7 Two-thirds to fully. 
Total...| 225 soefeoe ie | il = ee | 33 
At a mean temperature of 79.05° F. molting began on the four- 
teenth day after dropping. When the mean temperature fell to 
53.98° F. 76 days elapsed before molting began. This and the other 
long molting period given in the table were recorded on larve col- 
lected from wild hosts, and although the state of engorgement of the 
ticks was not recorded, there is little doubt that they were not fully 
engorged. This would tend to lengthen the molting period as has 
been found true in all observations made by us on this point. A 
total effective temperature of 505° F. appears to be required for this 
transformation. 
TABLE XXX.— Molting of engorged larve of Hemaphysalis chordeilis. 
Temperature from 
Engorged larve molted—Days following dropping. dropping to date 
first tick molted. 
Date 
Num- oe poe Si as a ep o5 
engorged | Host. | ber of |_| | a 
dropped larve. | | Total Maxt: | Mini Aver- 
: . ee ‘ axi-| Mini-| age 
14, 15)16 17/18 19) 21 96 bar fag 67 |76 | 92 ere ernae lscecet a ae 
heed ‘ mean. 
ETS. het EE STU RD ke ES A a2 
1909. Sean ome i Say: Nee 
Sept. 12] Rabbit.| 6 go oe ee et ie. Pee OPA [Bos Wee ae 3 | 98.50 | 59 79. 84 
ee 200.00). 9) Ate. -|ou Be Tete desk bth c 6 | 96.50 | 59 79.05 
Sept. 14 |...do CRASS, iy Rie pt TE 4 ties pis feattey: let hogareg, 1 te 1 | 95.50 | 56 77. 28 
Sept. 17 |...do 2 5 ee ot es ae es ee ASE oS eR 21 95.50 | 56 76.75 
Sept. 25 |...do 1 Ae U2. IEC EAS SES yg EA ER a 1 | 92.50 | 51 72. 38 
Sept. 30 |...do 1 alg eae (ee ea PA Sa) 1 | 92. 50 | 51 72.77 
or) 2 |. --d0 2 a is | sg CE Ee BG ER ee eae 2 | 92.50 | 52.50 | 73.80 
Oct. 3 |...do 3 des | ON celics es Hi Ber 1/92:50/52 | 72.88 
mre 16 |..2....- 6 cles el Cis Oe ES tae OS a 2| 79 20 | 53.98 
Nov. 25 | Meadow- 
lark pg See (479 Pee ee ae ey am ek ea ee 4} 4 | 79 20 52. 96 
Total..| 36+ |...| | | “Taw See | > Seeker 
1 Three of these molted before Jan. 31, 1910, and one on that date. 
The nymph (Table XX XI).—On account of the sparsity of material 
at hand, our records on the longevity of nymphs are fragmentary. 
One nymph which molted from a larva about January 22, 1910, was 
alive on April 6, 1910, when it was put on a host. This individual 
had lived 74 days, which is the longest period recorded by us. One 
nymph which molted February 15, 1910, died 16 days later. Two 
